SH/T 0773-2005 Test method for life characteristics of automotive wheel hub bearing grease

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: SH/T 0773—2005
• Chinese full name: Test method for life characteristics of automotive wheel hub bearing grease
• English name: Standard test method for life performance of automotive wheel bearing grease
• Replacement relationship: not provided in the available source (the foreword does not mention replacement of any standard)
• Adoption relationship: modified adoption of ASTM D3527-02 "Test method for life characteristics of automotive wheel hub bearing grease", redrafted according to ASTM D3527-02
• Main differences from ASTM D3527-02:
  • Some referenced standards in ASTM D3527-02 were changed to the corresponding Chinese industry standards
  • The cleaning reagent Penetone ECS in the adopted standard was changed to analytical grade acetone
  • The informative annex X2 "Bearing life test (h)" in ASTM D3527-02 was not adopted
• Editorial modifications: Figure 4 and Figure 5 were merged into Figure 4; the wording of repeatability and reproducibility was modified according to Chinese practice; the keywords clause in ASTM D3527-02 was deleted
• Publication/implementation: published on 2005-10-10, implemented on 2006-02-01
• Issuing authority: National Development and Reform Commission of the People's Republic of China
• Technical committee: Sinopec Research Institute of Petroleum Processing
• Drafting organization: Sinopec Research Institute of Petroleum Processing
• Main drafters: Yang Wei, Yao Zhiqin
• Annexes: Annex A is an informative annex

2. Scope of application and non-application

• 1.1 This standard specifies the laboratory evaluation procedure for the high-temperature life characteristics of automotive wheel hub bearing grease under given test conditions.
• 1.2 In this standard, except that equipment-related data use English units, all others use International System of Units SI units.
• 1.3 The use of this standard may involve hazardous materials, operations and equipment. This standard does not point out all safety problems involved in its use; therefore, users should establish appropriate safety and protective measures and determine applicable management regulations before using this standard.
• 5.1 This test method can distinguish wheel hub bearing greases with obviously different performance. The subsequent text source-text extraction of this clause in the source is incomplete ("the purpose is also not to distinguish those with similar ..."), requires confirmation against the source standard (source-text extraction).
• 5.2 This test method has been proven ... (the subsequent text source-text extraction of this clause in the source is incomplete), requires confirmation against the source standard (source-text extraction). The source also contains residual sentences such as "not adding grease is not equivalent to a long-term use test", requires confirmation against the source standard (source-text extraction).

3. Method principle

• 4 Method summary: Add the grease to be tested into a modified automotive front wheel hub-spindle-bearing assembly. When the axial load on the bearing is applied to 111N, the hub rotates at a speed of 1000r/min, the spindle temperature is maintained at 160°C, and the operating cycle is running for 20h and stopping for 4h. When the drive motor torque exceeds the set interruption value due to grease failure, the test ends. The grease life is expressed as cumulative running hours.
• Note: The stopped-running time within the 20h running and 4h stopped-running cycle is not recorded, and the stopped-running time is not accumulated into the grease life.

4. Reagents and materials (purity / preparation)

• 8.1 n-Heptane: analytical grade. Warning—flammable, inhalation ... (the source is incomplete, requires confirmation against the source standard (source-text extraction))
• 8.2 Isopropanol: analytical grade. Warning—flammable, inhalation ... (the source is incomplete, requires confirmation against the source standard (source-text extraction))
• 8.3 Acetone: analytical grade. Warning—combustible, vapor harmful.
• 8.4 Solvent naphtha: conforms to SH 0005. Warning—combustible, vapor harmful.
• 8.5 SAE 10W Engine oil.
• 8.6 00 steel wool.
• Note: The warning statements 8.1, 8.2 in the source are incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction).

5. Apparatus and equipment

• 6.1 Test apparatus, as shown in Figure 1 (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• 6.1.1 According to conventional appearance ... (the source is incomplete, requires confirmation against the source standard (source-text extraction))
• 6.1.2 Spindle-bearing assembly, as shown in Figure 3.
• 6.1.3 Spindle drive ... controls the spindle temperature to be constant at 160°C±1.5°C. ... 1725r/min, 120V DC control; motor torque ... on the instrument that shuts down the machine. (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• 6.1.4 Fan drive ... 1550r/min, 120V DC.
• 6.2 Accessory devices: ... rate, box temperature, shaft temperature, running time and torque. (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• 6.3 Balance: minimum ... (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• Figure 1 Wheel hub bearing grease testing machine (front view) components: 1— bearing loading device; 2—TC thrust rod; 3— thermometer jacket; 4— temperature measuring head; 5— wheel hub; 6— heat insulation layer; 7— sliding door; 8— drive connector; 9— drive motor, 1/4HP, 1725r/min, 120V; 10— electric lifter; 11— ...; 12— ...; 13— ...; 14— ...; 15— ...; 16— motor horizontal adjustment screw; Note: dimensions ... (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• Figure 2 Wheel hub bearing grease testing machine (top view) components: 1— built-in bearing (LM67048 bearing cone, LM67010 bearing outer ring); 2— bearing loading device; 3—TC thrust rod; 4— heater; 5— fan motor (1/30HP, 1550r/min); 6— motor bracket; 7— drive hub; 8— motor support; 9— motor; 10— electric lifter; 11— tail nut; 12— external bearing (LM11949 bearing cone, LM11910 bearing outer ring); 13— temperature measuring head; 14— wheel hub; 15— spindle; 16— grease leakage collector.
• Figure 3 Spindle and push rod components: (A) rod; (B) rod guide plate; (C) spindle; (D) compression plate and rod limiter; (E) rear plate; (F) spring; (G) compression nut; (H) lock nut; (I) tail nut; (J) compression gauge.
• Figure 4 Bearing greaser: material is stainless steel; Note: for dimension conversion see Annex A.

6. Recommended operating conditions

• Axial load: 111N (25 lbf)
• Rotational speed: 1000r/min±50r/min
• Spindle temperature: 160°C±1.5°C
• Operating cycle: running 20h, stopped running 4h
• Motor interruption value is determined according to formula (1): C = 8 (T−N) + N
• Note: There is a 30s delay time to protect the motor.

7. Sampling and specimen preparation

• 7 Test bearings: respectively use LMG ... 2704 ... LM11910CAFBMA standard 19 as built-in bearings. (the source is severely incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• 9 Bearing preparation:
  • 9.1 Carefully take the new bearing (bearing outer ring and bearing cone) out of the package and place it into a 250mL beaker, clean with n-heptane to remove all rust preventive.
  • 9.2 Repeat cleaning twice more with n-heptane to ensure all rust preventive is removed. A clean beaker must be used each time.
  • 9.3 Drain the n-heptane from the bearing and place the bearing on a clean silk cloth to air dry.
  • Note: An ultrasonic cleaner may be used to clean the bearing.
• 10.3 Weigh the built-in and external bearing cones to the nearest 0.1g (the "0.4g" in the source is suspected to be source-text extraction noise, requires confirmation against the source standard (source-text extraction)). Use another set of bearing outer rings and the grease greaser shown in Figure 4 to add the specimen into the bearing cone. When taking the bearing cone out of the bearing outer ring and during subsequent wiping and other operations, avoid rotating the rollers or moving bearing components. Use a scraper to scrape off excess grease overflowing from the front side of the bearing cone (near the small end of the rollers), wipe the rear side of the bearing cone, the outer surface of the cage and the surfaces of exposed rollers with a clean silk cloth, and weigh again. By wiping or adding grease into the groove between the bearing cage and the rear side of the bearing cone, adjust the grease mass in the built-in bearing cone to 3.0g±0.1g, and the grease mass in the external bearing cone to (the source value source-text extraction is incomplete, requires confirmation against the source standard (source-text extraction)) 0g±0.1g. Apply a thin layer of grease on the bearing outer ring.

8. Analytical procedure

• 10.1 Before each test ... and the spindle hole. Check the free movement of the longitudinal load handle in the spindle (Figure 3); if there is sticking, take out and clean the handle. (the source is incomplete at source-text extraction, requires confirmation against the source standard (source-text extraction))
• 10.2 Install the bearing outer ring into the cleaned wheel hub according to the positions in Figure 1 and Figure 2. (the "Figure work" in the source is suspected to be source-text extraction noise, requires confirmation against the source standard (source-text extraction))
• 10.3 See Section 7 for specimen preparation.
• 10.4 Install the grease leakage collector, built-in bearing cone, wheel hub and external bearing cone on the spindle as shown in Figure 2, fix the components in place with the tail nut, and install the spindle connector.
• 10.5 Referring to Figure 3, adjust the axial load according to the following steps: tighten the compression nut G until the spring F is at the position just against the rear plate E, but not compressed. Screw the lock nut H to G without moving H, and by tightening G compress F until the gauge J is clamped between H and G. Keep J in place and turn back G until J is tightly clamped between H and G.
  • Note: The compression gauge J has the following function: inserting the compression gauge and adjusting G can compress the spring F and apply an axial load of 111N (25 lbf) to the wheel hub bearing.
• 10.6 Insert the thermocouple into the spindle push rod and position the contact point at the center of the outer bearing. Close the oven and place the motor in the operating position.
  • Warning: At this time, do not connect the motor with the drive connector. Start the motor and adjust the speed to 1000r/min±50r/min. At this time, observe and record the no-load motor current value N.
• 10.7 Stop the motor, connect the drive connector and secure it in a suitable position, set the time, and begin the 20h operating cycle. Restart the motor and again adjust the speed to 1000r/min±50r/min, turn on the heater and adjust the oven temperature until the shaft temperature is controlled at 160°C±1.5°C. After the shaft temperature stabilizes at the test temperature, do not adjust the oven temperature again during the test.
• 10.8 When operation begins, a stable operating torque will be generated within 2h, and a stable current will be displayed on the meter. Record this value as the stable current value T. Determine the motor interrupt value according to formula (1): C = 8 (T−N) + N. Set the motor interrupt value to C.
• 10.9 Operate the testing machine under the specified load, speed, and temperature conditions until the motor torque exceeds the set torque limit. When this point is reached, the motor automatically stops. Record the stop time.
  • Note: There is a 30s delay time to protect the motor.
• 10.10 Cool the testing machine to a safe operating temperature and disassemble it. If disassembling the testing machine at high temperature, wear heat-insulating gloves.
• 11 Parts cleaning:
  • 11.1 Use a suitable scraper to scrape off as much grease as possible from the grease collector, tail nut, and spindle connector.
  • 11.2 Place the parts into a suitable container (preferably a stainless steel container) and cover with acetone, cover but leave a certain gap and slightly heat (70°C±10°C) until the parts are clean (about several hours). Avoid heating for too long (overnight) to prevent corrosion of the parts.
  • 11.3 Remove the parts from the solvent, wash with running hot water and immediately rinse with isopropyl alcohol, and dry in air. If the parts are not to be used immediately, coat with a layer of SAE 10W engine oil.
  • 11.4 Use a suitable scraper to scrape off the grease on the spindle, then wipe off the remaining grease on the spindle with 00 steel wool and solvent oil. If the residue bonded to the spindle cannot be removed, take out the spindle and wash it with acetone.

9. Qualitative and Quantitative and Calculation Formulas

• Grease life is expressed as cumulative operating hours (see the method summary in Section 4).
• Motor interrupt value calculation formula (1):
  • C = 8 (T−N) + N
  • Where: C— motor interrupt value, A; T— stable current value, A; N— motor no-load current value, A.

10. Precision

• 13 Precision and bias (95% confidence level):
  • 13.1 Repeatability: The difference between two results obtained by the same operator using the same instrument on the same sample shall not exceed the requirement of formula (2):
    • T = 0.8X (2)
    • Where: X— the average of the two test results.
  • 13.2 Reproducibility: The difference between two individual test results obtained by different operators in different laboratories on the same sample shall not exceed the requirement of formula (3):
    • R = 1.2X (3)
    • Where: X— the average of the two test results.
  • 13.3 Bias: Since the grease life value is defined only in this test method, this test method has no bias. (This clause source-text extraction in the source text is incomplete, requires confirmation against the source standard (source-text extraction))

11. Report

• 12 Report: Report the number of hours at the termination of the test.

12. Referenced Documents

• SH 0005 Solvent oil for paint industry
• Anti-Friction Bearing Manufacturers Association AFBMA Standard 19, 1974 (American National Standard ANSI B.3.19-1975)
• ASTM D3527-02 (the original standard modified and adopted)

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Q&A Reference